... And then if I want to keep going I need to also buy Lion, Mountain Lion, and finally Mavericks if I want to right?
Not quite. You need to purchase Snow Leopard first:
Elsewhere: call the phone number in the Apple Online Store
Apple's price is $19.99 or £14.00 or 18,00 €. It is not available to download from any legitimate source (institutional / corporate deployments excepted).
Make sure your system meets Snow Leopard's requirements:
Mac OS X 10.6 "Snow Leopard" System Requirements
To install Snow Leopard for the first time, you must have a Mac with:
- An Intel processor
- An internal or external DVD drive, or DVD or CD Sharing
- At least 1 GB of memory (RAM) (additional RAM is recommended)
- A built-in display or a display connected to an Apple-supplied video card supported by your computer
- At least 5 GB of disk space available, or 7 GB of disk space if you install the developer tools
After you install Snow Leopard you can decide if you want to upgrade OS X to the latest version, Mountain Lion. Mountain Lion is available in the Mac App Store, which is available to you after upgrading to Snow Leopard. System requirements for Mavericks are expected to be identical to Mountain Lion.
Make sure your system meets the requirements for Mountain Lion:
Mac OS X 10.8 "Mountain Lion" System Requirements
To install Mountain Lion, you need one of these Macs:
- iMac (Mid 2007 or newer)
- MacBook (Late 2008 Aluminum, or Early 2009 or newer)
- MacBook Pro (Mid/Late 2007 or newer)
- MacBook Air (Late 2008 or newer)
- Mac mini (Early 2009 or newer)
- Mac Pro (Early 2008 or newer)
- Xserve (Early 2009)
Your Mac needs:
- Mac OS X 10.6.8 "Snow Leopard" or OS X 10.7 "Lion" already installed
- 2 GB or more of memory (RAM)
- 8 GB or more of available hard disk space
a brody's Mountain Lion upgrade summary, which contains more detail than the above: https://discussions.apple.com/docs/DOC-3761
If your system does not support Mountain Lion's requirements, you may be able to upgrade to Lion. To do that you must phone Apple to order a download code. Redeem the download code in the App Store to download Lion.
Make sure your system meets the requirements for Lion:
Mac OS X 10.7 "Lion" System Requirements
- Mac with an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon CPU
- Core Duo CPUs are not sufficient for Lion
- 2GB of memory (RAM)
- Mac OS X 10.6.8 "Snow Leopard" already installed (update any 10.6.x version to 10.6.8)
To determine which Mac you have, what kind of CPU it uses, and how much memory is installed: > About This Mac
The specified 2 GB minimum is barely adequate for either Lion or ML. They will run in 2 GB but you are likely to find its performance unacceptable. 4 GB is a more realistic minimum. 6 GB or more will be comfortable.
Upgrading to Snow Leopard
You can purchase Snow Leopard through the Apple Store: Mac OS X 10.6 Snow Leopard - Apple Store (U.S.). The price is $19.99 plus tax. You will be sent physical media by mail after placing your order.
After you install Snow Leopard you will have to download and install the Mac OS X 10.6.8 Update Combo v1.1 to update Snow Leopard to 10.6.8 and give you access to the App Store. Access to the App Store enables you to download Mountain Lion if your computer meets the requirements.
Snow Leopard General Requirements
1. Mac computer with an Intel processor
2. 1GB of memory
3. 5GB of available disk space
4. DVD drive for installation
5. Some features require a compatible Internet service provider;
fees may apply.
6. Some features require Apple’s iCloud services; fees and
If you decide to upgrade further:
Upgrading from Snow Leopard to Lion or Mountain Lion
You can upgrade to Mountain Lion from Lion or directly from Snow Leopard. Mountain Lion can be downloaded from the Mac App Store for $19.99.
If you sign into the App Store and try to purchase Mountain Lion but the App Store says your computer is not compatible then you may still be able to upgrade to Lion per the following information.
A. Upgrading to Mountain Lion
To upgrade to Mountain Lion you must have Snow Leopard 10.6.8 or Lion installed. Purchase and download Mountain Lion from the App Store. Sign in using your Apple ID. Mountain Lion is $19.99 plus tax. The file is quite large, over 4 GBs, so allow some time to download. It would be preferable to use Ethernet because it is nearly four times faster than wireless.
Macs that can be upgraded to OS X Mountain Lion
1. iMac (Mid 2007 or newer) - Model Identifier 7,1 or later
2. MacBook (Late 2008 Aluminum, or Early 2009 or newer) - Model Identifier 5,1 or later
3. MacBook Pro (Mid/Late 2007 or newer) - Model Identifier 3,1 or later
4. MacBook Air (Late 2008 or newer) - Model Identifier 2,1 or later
5. Mac mini (Early 2009 or newer) - Model Identifier 3,1 or later
6. Mac Pro (Early 2008 or newer) - Model Identifier 3,1 or later
7. Xserve (Early 2009) - Model Identifier 3,1 or later
To find the model identifier open System Profiler in the Utilities folder. It's displayed in the panel on the right.
Are my applications compatible?
For a complete How-To introduction from Apple see Upgrade to OS X Mountain Lion.
B. Upgrading to Lion
If your computer does not meet the requirements to install Mountain Lion, it may still meet the requirements to install Lion.
You can purchase Lion by contacting Customer Service: Contacting Apple for support and service - this includes international calling numbers. The cost is $19.99 (as it was before) plus tax. It's a download. You will get an email containing a redemption code that you then use at the Mac App Store to download Lion. Save a copy of that installer to your Downloads folder because the installer deletes itself at the end of the installation.
Lion System Requirements
1. Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7,
or Xeon processor
2. 2GB of memory
3. OS X v10.6.6 or later (v10.6.8 recommended)
4. 7GB of available space
5. Some features require an Apple ID; terms apply.